1. Technical Field
The present invention relates to a process for the continuous permanent decatizing and fixing of textile materials in web form, such as woven or knitted fabrics or the like. The invention is particularly applicable to wool or wool mixture fabrics.
The permanent decatizing effects concerned here are particularly those effects which cannot be detrimentally affected by the use of steam ironing presses at clothing manufacturers. As is known, non-permanent decatizing effects lose their character of gloss, feel and look on steaming and pressing.
2. Prior Art
Permanent decatizing effects can be achieved as a rule only with discontinuous processing arrangements, e.g. with the aid of a decatizing boiler machine. In such processing arrangements the fabric and the backing cloth are wound together around a decatizing and treatment cylinder, and subsequently treated in an autoclave under high temperature conditions.
The drawback with such discontinuous processes is exacerbated by a further drawback, that is the effects achievable within each square--i.e. between the start and end of the material--turn out to be considerably different.
U.S. Pat. No. 4,912,792 describes a process making it possible to achieve in a continuous manner, permanent decatizing effects. Essentially, what is disclosed is the fact that chemical fixing agents have to be used in parallel with the physical effect of the decatizing, so that a permanent degree of fixing can be ensured. According to this known method the chemical fixing agents are applied with the addition of hygroscopic substances in the region of a foulard--thus at a stage before the stretching and drying process.
Immediately before the actual decatizing and fixing process an activation of the fixing agent is achieved by controlled redamping. The fixing agent activated by the damping is reacted with the application of heat and mechanical pressure in the fibre structure of the material in the region of the decatizing and fixing equipment.
Although by means of this known method permanent decatizing effects are achieved with a continuous operation, this method has not so far been able to establish itself to a great extent because many users, e.g. cloth makers or the like are reluctant to use chemicals, particularly avoiding this in the region of the drying equipment. A further drawback lies in the cost of constant procurement of these chemical fixing agents. For countries which are poor in hard currency there is the problem of obtaining chemicals.